Network File System Abbreviated NFS. A distributed file-sharing system developed well over a decade ago by Sun Microsystems, Inc.
NFS allows a computer on a network to use the files and peripheral devices of another networked computer as if they were local, subject to certain security restrictions. Using NFS, you can share files on your system with other computers running MS-DOS, MacOS, Unix, Novell NetWare, VMS, and many other operating systems, in both local
and global environments. NFS is platform-independent and runs on mainframes, minicomputers, RISC-based workstations, diskless workstations, and personal computers.
OSI Reference Model : A networking reference model defined by the ISO (International Organization for Standardization) that divides computer-to-computer communications into seven connected layers. Suchlayers are known as a protocol stack. Each successively higher layer builds on the functions of the layers below, as follows:
- Application layer :The highest level of the model. It defines the manner in which applications interact with the network, including database management, e-mail, and terminal-emulation programs.
- Presentation layer : Defines the way in which data is formatted, presented, converted, and encoded.
- Session layer : Coordinates communications and maintains the session for as long as it is needed, performing security, logging, and administrative functions.
- Transport layer : Defines protocols for structuring messages and supervises the validity of the transmission by performing some error checking.
- Network layer : Defines protocols for data routing to ensure that the informationarrives at the correct destination
- Data-link layer : Validates the integrity of the flow of data from one node to another by synchronizing blocks of data and controlling the flow of data.
- Physical layer : Defines the mechanism for communicating with the transmission medium and interface hardware.
Network A group of computers and associated peripheral devices connected by a communications channel capable of sharing files and other resources among several users.A network can range from a peer-to-peer network connecting a small number of users in an office or department, to a LAN connecting many users over permanently installed cables and dial-up lines, to a MAN or WAN connecting users on several networks spread over a wide geographic area.
Electronic mail (e-mail) is one of the popular services available on Internet hosts. E-mail software comes in two parts: a mail transport agent (MTA), which physically sends and receives mail messages, and a mail user agent (MUA), which reads messages and prepares new messages.
sendmail’s configuration file /etc/mail/sendmail.cf in Fedora and /etc/sendmail.cf
The sendmail mail transfer agent, you can use the mail command to compose and send a mail message to any user account on your Linux system. As a test, compose a message and send it to yourself.
For example,
mail edulaney
Subject: Testing e-mail
This is from my Linux system.
.Cc: but leave that blank.
After ending the message, the mail user agent passes the message to sendmail (the mail transport agent) for delivery to the specified address. sendmail delivers the mail message immediately.
To verify the delivery of mail, type mail to run the mail command again and read the message. Thus, the initial sendmail configuration file is adequate for sending and receiving e-mail, at least within your Linux system.
A free, Unix-compatible, 32-bit operating system developed in 1991 by Linus Torvalds while at the University of Helsinki in Finland.
Strictly speaking, Linux is the name of the operating system kernel, the central part of the operating system that manages system services, but many people use the name to refer to the complete operating system package, including utilities, editors and compilers, games, and networking components. Many of these important elements are actually part of the Free Software Foundation’s GNU Project, and others have been written and released by volunteers.
Linux is supported and distributed by companies such as Red Hat Software, Caldera Software, Workgroup Solutions, Walnut Creek Software, and S.u.S.E. of Germany. With the increasing use of Linux in the corporate world, several major companies have announced some level of support for the operating system, including Hewlett-Packard, Silicon Graphics, Sun Microsystems, and Intel, and several major applications packages have been ported to Linux,
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